1. Field
The present invention relates to a mobile robot, and, more particularly, to an apparatus, method, and medium for allowing a mobile robot to simultaneously perform a cleaning process and a map-creating process.
2. Description of the Related Art
In general, industrial robots were developed to improve factory automation, and perform manufacturing processes in extreme environments in which the humans cannot work. In recent years, robotics technology has been used in the space industry, which has lead to the development of human-friendly home service robots. In addition, robots can be inserted into the human body instead of medical instruments to treat a minute cellular texture, which is untreatable using existing medical instruments. Robotics technology has drawn attention as possible technology to follow the information revolution caused by the development of the Internet and biotechnology.
Home service robots, such as cleaning robots, have played a leading role in the expansion of robotics technology focused on industrial robots used for only heavy industries to robotics technology focused on light industries. The cleaning robot generally includes a driving unit for movement, a cleaning unit, and a positioning unit for measuring the position of a user or a remote controller.
In the mobile robots, such as cleaning robots, it is a basic and important function to check its exact position. The absolute position of the mobile robot can be calculated by the following methods: installing a beacon having an ultrasonic sensor in the home; using indoor GPS (global positioning system). In addition, the relative position of the mobile robot can be calculated by the following methods: calculating the rotational speed of a mobile robot and the linear speed of the mobile robot using an encoder and integrating the speeds; integrating an acceleration value obtained by an acceleration sensor twice; and integrating the rotational speed of the mobile robot, which is the output of a gyro-sensor, to calculate a traveling direction.
However, the mobile robot needs to create a map in order to perform a specific process, such as cleaning, in a space. In order to create the map, a separate algorithm for exploring an unknown area in addition to SLAM (simultaneous localization and mapping) is needed. The following methods are used as the algorithm: determining the overall shape of a space using wall-following; and planning a coverage path using active SLAM. After the map is created by the above-mentioned methods, a separate coverage-path-planning process for allowing the mobile robot to clean all of the areas included in the map is needed.
That is, in the related art, the mobile robot needs to perform a position-recognizing process for creating a map, a map-creating process, and a coverage-path-planning process for cleaning the entire space using the created map, in order to clean the entire space. As a result, cleaning time is lengthened. In addition, the accuracy of the map is important to make the coverage-path plan for cleaning the entire space, but an inexpensive obstacle sensor cannot meet the accuracy requirement. In particular, when a sensor provided in the mobile robot has a short sensing distance, it is difficult to create a map for the entire space using only a wall-following method.